Energy saving thermostats of the type disclosed in John T. Adams, et al, U.S. Pat. No. 4,316,577 for Energy Saving Thermostat issued Feb. 23, 1982, are presently being marketed by the applicants' assignee in the form of the T8100A Microelectronic Chronotherm Fuel Saver Thermostat. In such a thermostat, the normal control temperature can be offset by a selected amount during an energy saving time period of the day. To program the energy saving time period, the home owner pushes a button at the time energy saving time period is to begin to close a switch which stores a time in hours depending upon the number of flashes of an indicator light. For example, if an eight hour energy saving time period offset of the normal temperature is to begin at 10:00 P.M., the home owner would wait until 10:00 P.M. to push the program button and store in the memory the eight hour period of time. Each twenty-four hours, the thermostat controls at an energy saving temperature which is offset from the normal control temperature for the eight hour period until a new energy saving time period was selected and stored in the memory.
The present invention is concerned with an improvement to such a thermostat to provide for changing or readjusting the starting time for the selected time period. The readjustment of the time period can be made either back or ahead at any time by pushing one or more buttons to close associated switches.